1. Field of the Invention
The present invention relates to novel, herbicidally active picolinic acid derivatives and to processes for preparation thereof and the intermediates used therein. The present invention further provides for the use thereof as a herbicide, especially as a herbicide for selective control of weed plants in useful plant crops, and as a plant growth regulator alone or in combination with safeners and/or in a mixture with other herbicides.
2. Description of Related Art
WO 01/51468 describes herbicidally active picolinic acids. In contrast to the present invention, the picolinic acids described therein, however, do not have any aryl or hetaryl substituents in the 6 position of the picolinic acid.
WO 03/011853 describes herbicidally active picolinic acids which may bear, in the 6 position, aryl or heteroaryl groups which in turn may have further substituents. In contrast to the present invention, the prior art, however, does not teach picolinic acids which have, in the 6 position, aryl or hetaryl substituents which are themselves in turn substituted by heterocyclyl groups.
WO 2007/092184 discloses, inter alia, picolinic acids which may be substituted in the 6 position by aryl or heteroaryl groups. However, the prior art does not disclose that the aryl or heteroaryl groups in the 6 position of the picolinic acid may themselves be substituted by heterocyclic groups.
Applications WO 2007/082098, US 2008/0045734, US 2008/0051596 and US 2009/0088322 disclose herbicidally active picolinic acids which bear aryl groups in the 6 position. These may in turn bear further substituents, but not heterocycles.
The herbicidally active picolinic acids disclosed in US 2004/0198608 do not have any aryl or heteroaryl radicals in the 6 position.
WO 2009/081112 discloses herbicidal pyrimidines which bear substituted amines in the 6 position. However, the active herbicidal ingredients known in the prior art have disadvantages on use thereof, for example that they have (a) only inadequate, if any, herbicidal action against weed plants, (b) too small a range of weed plants controlled, or (c) too low a selectivity in useful plant crops.
It is therefore desirable to provide chemical active ingredients which do not have the disadvantages of the prior art and can be used as herbicides or plant growth regulators.